Conductive laminate and touch panel using same

ABSTRACT

A touch panel that not only demonstrates little deterioration of performance even in harsh environments at high temperature and high humidity, but is also free of the occurrence of a whitening phenomenon occurring during sudden changes in temperature and humidity, while also having superior shock resistance. A conductive laminate in which a uniform or arbitrarily patterned conductive layer containing a polythiophene-based conductive agent and an adhesive layer containing an acidic component are in direct contact over the entire surface or a portion thereof, and a touch panel in which it is used.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/576,608, filed Aug. 1, 2012, which is the U.S. National Phase under35 U.S.C. §371 of International Application No. PCT/JP2011/052614, filedFeb. 8, 2011, designating the U.S., and published in Japanese as WO2011/099474 on Aug. 18, 2011, which claims priority to Japanese PatentApplication No. 2010-026732, filed Feb. 9, 2010, the content of which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a conductive laminate suitable for useas a constituent member of a touch panel that not only has lowperformance variation in harsh environments such as high-temperature,high-humidity environments, but also does not exhibit a whiteningphenomenon occurring during sudden changes in temperature or humidity,while also having superior shock resistance.

BACKGROUND ART

Touch panels are electronic components that function as location inputdevices, and are used in a wide range of applications such as cellphones or portable game devices by combining with a display device inthe manner of a liquid crystal panel. A touch panel is an interfacecapable of performing a suitable operation desired by an operator bysensing information relating to a specific location when the operatorpoints to that specific location on the touch panel with a finger orinput pen based on a screen display.

Although touch panels employ methods based on various principles todetect a pointed location, a detection method employing a resistive filmhas been widely used thus far. The resistive film detection methodinvolves detecting a location based on a voltage between two opposingtransparent, conductive films. When a voltage is applied to one of thetwo films, a voltage corresponding to a location of the transparentconductive film that has been operated is generated in the othertransparent conductive film. The location that has been operated can bespecified by detecting that voltage.

On the other hand, in addition to touch panels being highly accurate,highly durable and highly sensitive, following the development ofmulti-touch systems in recent years, the use of electrostatic capacitivetouch panels has rapidly proliferated primarily in mobile devices suchas cell phones. With the growth of devices in which these touch panelsare installed and the environment in which they are used, along withincreasing diversification of the types of these touch panels that areavailable, these touch panels are expected to surpass the number ofresistive film types in the future.

Two examples of typical detection methods employed by electrostaticcapacitive touch panels include analog detection surface types andprojective types employing an integrating detection system usingpatterned electrodes. Moreover, although numerous proposals have beenmade for each system and manufacturer for the configuration ofprojective types, many projective types that have recently demonstrateda sudden increase in popularity impart durability by using a glass orresin plate for the protective plate of the insulating layer interposedbetween conductive layers or the surface. In the future, the use ofvarious types of resin film films for these components is expected toresult in a growing trend towards reduced costs and increasedflexibility.

Since the conductive layer serving as a critical component of touchpanels is intended to demonstrate both conductive performance andtransparency, an ITO (indium tin oxide) layer formed by a dry methodsuch as sputtering or vapor deposition is used most commonly.

However, since dry ITO layers are comparatively brittle and have lowshock resistance due to their production method and components, there isthe risk of damage due to impacts resulting from dropping and the like.Moreover, since they are also susceptible to bending, when a film isused to make the structural materials of a touch panel flexible, thereis the risk of considerable decrease in durability. Therefore, studieshave been conducted on the use of a conductive layer formed by a wetmethod that is capable of improving shock resistance and bendability.

Although there are various types of materials used for conductive layerscapable of being formed by a wet method, including metal oxide-basedmaterials such as ITO or ATO, metal-based materials such as silver orcopper, and conductive carbon nanofibers, if the emphasis is placed onbendability, then organic conductive polymers are preferable.

In particular, numerous studies are being conducted onpolythiophene-based since they are capable of realizing both electricalconductivity and transparency. However, since these polymers areprepared in the form of an aqueous dispersion, there are concerns overwetting following deposition as well as decreases in quality when usedin high-humidity environments. Therefore, Patent Document 1 proposes theformation of a protective layer by thermal bonding a transparentinsulating sheet to a conductive layer composed of a conductive polymer.

In addition, in the case of touch panels, there are many cases in whichconductive layers are used as members by laminating with an adhesive,and in the case of projective-type, electrostatic capacitive touchpanels in particular, this configuration is employed over nearly theentire display screen.

However, in the case of dry ITO layers that were used most commonly inthe past, since corrosion of the conductive layer leads to inferiorquality when combined with an adhesive containing an acidic component,countermeasures have been proposed and used in finished productsconsisting of, for example, using an adhesive that does not contain anacidic component as is proposed in Patent Document 2.

PRIOR ART DOCUMENTS Patent Documents

-   [Patent Document 1] Japanese Patent Application Laid-Open No.    2007-052975-   [Patent Document 2] Japanese Patent Application Laid-Open No.    2009-079203

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

However, even if a protective layer is provided as is proposed in PatentDocument 1, it was not possible to adequately achieve stable qualityunder harsh conditions of high temperature and high humidity. Inaddition, this technique is also unsuitable since it invites increasethickness and increased costs resulting from an increase in the numberof members.

On the other hand, in the case a conductive layer is used by laminatingwith an adhesive, although the adhesive layer can be expected tofunction as a protective layer, components flowing out from the adhesivelayer have a detrimental effect on the conductive layer. Therefore, evenif an adhesive of quality determined in consideration of combining witha conductive layer in the form of an ITO layer is laminated as proposedin Patent Document 2, the increase in resistance of the conductive layerin a high-temperature, high-humidity environment was converselyremarkable in comparison with the case of not laminating an adhesivelayer. Moreover, since this laminate has the characteristic of becomingcloudy and white when the environment changes from a high-temperature,high-humidity environment to a temperature and humidity of an ordinaryenvironment, it resulted in impairment of touch panel visibility.

Therefore, an object of the present invention is to allow the obtainingof a conductive layer demonstrating favorable durability even in harshusage environments while using a polythiophene-based conductive polymeras a conductive layer that has strong shock resistance and bendabilityand is capable of being compatible with reduced costs. Moreover, anobject of the present invention is to overcome the problem of thewhitening phenomenon that occurs during sudden changes in temperature orhumidity, considered to be one of the shortcomings of conventional ITO.

Means for Solving the Problems

The present invention employs the following configurations to achievethe aforementioned objects.

[1] A conductive laminate including: a uniform or arbitrarily patternedconductive layer, an adhesive layer provided in direct contact over theentire surface or a portion of the conductive layer, and an extractingelectrode in contact with both the conductive layer and the adhesivelayer, which a portion of the extracting electrode being sandwichedbetween the conductive layer and the adhesive layer, wherein theconductive layer containing a polythiophene-based conductive agent, theextracting electrode is formed by metal materials, and the adhesivelayer containing an acidic component.

[2] A conductive laminate including: a base material, a uniform orarbitrarily patterned conductive layer on the base material, an adhesivelayer provided in direct contact over the conductive layer, and anextracting electrode in contact with both the conductive layer and theadhesive layer, which a portion of the extracting electrode beingsandwiched between the conductive layer and the adhesive layer, whereinthe conductive layer containing a polythiophene-based conductive agent,the extracting electrode is formed by metal materials, and the adhesivelayer containing an acidic component.

[3] A conductive laminate including: a first base material, a uniform orarbitrarily patterned conductive layer on the first base material, anadhesive layer provided in direct contact over the conductive layer, anextracting electrode in contact with both the conductive layer and theadhesive layer, which a portion of the extracting electrode beingsandwiched between the conductive layer and the adhesive layer, and asecond base material provided on the adhesive layer, wherein theconductive layer containing a polythiophene-based conductive agent, theextracting electrode is formed by metal materials, and the adhesivelayer containing an acidic component.

[4] A conductive laminate including: an insulating layer, a uniform orarbitrarily patterned conductive layer on the insulating layer, anadhesive layer provided in direct contact over the conductive layer, andan extracting electrode in contact with both the conductive layer andthe adhesive layer, which a portion of the extracting electrode beingsandwiched between the conductive layer and the adhesive layer, whereinthe conductive layer containing a polythiophene-based conductive agent,the extracting electrode is formed by metal materials, and the adhesivelayer containing an acidic component.

[5] A conductive laminate including: an insulating layer, first andsecond conductive layers patterned into a shape having uniaxialregularity are laminated onto both sides of the insulating layer so thatthe patterns of the conductive layer are mutually perpendicular, a firstadhesive layer provided in direct contact over the first conductivelayer on the outer side of the first conductive layer, a second adhesivelayer provided in direct contact over the second conductive layer on theouter side of the second conductive layer, a first extracting electrodein contact with both the first conductive layer and the first adhesivelayer, which a portion of the first extracting electrode beingsandwiched between the first conductive layer and the first adhesivelayer, a second extracting electrode in contact with both the secondconductive layer and the second adhesive layer, which a portion of thesecond extracting electrode being sandwiched between the secondconductive layer and the second adhesive layer,

wherein the first and the second conductive layers containing apolythiophene-based conductive agent, the first and the secondextracting electrodes are formed by metal materials, and the first andthe second adhesive layers containing an acidic component.

[6] The conductive laminate according to any one of [1] to [5], whereinthe extracting electrode is formed by a silver paste.

[7] The conductive laminate according to any one of [1] to [5], whereinthe adhesive layer contains an acrylic polymer having a carboxyl groupor a derivative thereof.

[8] The conductive laminate according to any one of [1] to [5], whereinthe adhesive layer contains a copolymer comprising a unit derived fromone or both of butyl acrylate or ethylhexyl acrylate and a unit derivedfrom acrylic acid.

[9] The conductive laminate according to any one of [1] to [5], whereinthe polythiophene-based conductive agent comprises a polymer of one orboth of 3-hexylthiophene or 3,4-ethylenedioxythiophene, or a derivativethereof.

[10] A touch panel provided with the conductive laminate according toany one of [1] to [5].

[11] The touch panel according to [10], which is of the electrostaticcapacitive type.

Effects of the Invention

According to the conductive laminate of the present invention,durability in a harsh environment such as high temperature or highhumidity, favorable visibility and shock resistance can be imparted to atouch panel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a conductive laminate according toan embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conductive film according to anembodiment of the present invention.

FIG. 3 is a cross-sectional view of an adhesive sheet according to anembodiment of the present invention.

FIG. 4 is a cross-sectional view of an electrostatic capacitive touchpanel.

FIG. 5 is a cross-sectional view of a conductive laminate manufacturedbased on examples and comparative examples of the present invention.

FIG. 6 is an overhead view of a conductive laminate manufactured basedon examples and comparative examples of the present invention.

FIG. 7 is a drawing showing a method for evaluating bendability of aconductive laminate manufactured on the basis of examples andcomparative examples of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The following provides an explanation of embodiments of the conductivelaminate of the present invention and a touch panel provided therewith.

The conductive laminate of the present invention has a uniform orarbitrarily patterned conductive layer containing a thiophene-basedconductive agent and an adhesive layer containing an acidic component.Here, a “uniform” conductive layer indicates a layer used inanalog-type, resistive film-type touch panels, for example, in which thesurface that functions as a conductive layer is formed to a uniformthickness. In addition, an “arbitrarily patterned” conductive layerindicates a conductive layer used in projective-type, electrostaticcapacitive touch panels, for example, that has a regularly patternedshape formed for the purpose of detecting location, and the conductivelayer is either partially formed in advance by various types of printingmethods and the like, or a portion of a uniformly preformed conductivelayer is formed using wet etching using an etching solution or dryetching using laser light and the like followed by removal in a laterstep. However, even in the case of a uniform layer, a portion of theconductive layer may be patterned in order to form extracting electrodesand the like corresponding to the configuration of the touch panel.

[Conductive Laminate]

The conductive laminate of the present invention comprises a “conductivelayer and an adhesive layer facing the conductive layer”. Other films orsheet members and the like are laminated on the outsides of both layerscorresponding to the application. Although a cross-sectional view of aconductive laminate 1 is shown in FIG. 1 as an embodiment thereof, theconfiguration is not limited thereto. Furthermore, subsequentcross-sectional views and other drawings mainly indicate theconfiguration of component members, and are not intended to accuratelyrepresent individual dimensions since there are locations where thedimensions and thickness of each member are suitably emphasized.

In FIG. 1, after uniformly coating a coating solution to the basematerial 11 for a conductive layer, an adhesive layer 21 is adhered tothe surface of the conductive layer 12 that has been arbitrarilypatterned as necessary, and the opposite side of the adhesive layer iscovered with a first releasing base material 22.

(Conductive Layer)

The conductive layer of the conductive laminate of the present inventioncontains a polythiophene-based conductive agent as a conductivesubstance. Although polythiophene-based conductive agents areπ-conjugated organic conductive polymers that demonstrate electricalconductivity due to the presence of a main chain in which double bondsand single bonds are alternately arranged, since they exhibit lowabsorbance in the visible light region in particular, they are able toachieve high transparency. In particular, polymers (abbreviated as P3HT)of 3-hexylthiophene (abbreviated as 3HT) and derivatives thereof as wellas polymers (abbreviated as PEDOT) of 3,4-ethylenedioxythiophene(abbreviated as EDOT) and derivative thereof are preferable. Moreover,aqueous dispersions (abbreviated as PEDOT-PSS) obtained by polymerizingEDOT in the presence of polystyrene sulfonate (abbreviated as PSS),which not only fulfills the role of a dopant for enhancing electricalconductivity, but also functions as a dispersing agent, as well asPEDOT-PVS, which use polyvinyl sulfonate (PVS) instead of PSS, are morepreferable. In addition, self-doped polythiophenes, which have sulfonategroups in the main chain thereof, as well as derivatives of organicsolvent-dispersed PEDOT obtained by polymerizing with a flexible polymersuch as polyethylene glycol, may also be used corresponding to thecombined members, production method and usage conditions.

In addition, high boiling point solvents such as polyethylene glycol,methylformamide, dimethylsulfoxide or N-methylpyrrolidone, which havebeen confirmed to demonstrate effects that improve electricalconductivity, may also be added as secondary dopants to these PEDOT orderivatives thereof. In this case, the suitable amount of high boilingpoint solvent added is 10 to 500 parts by weight and more preferably 100to 300 parts by weight based on 100 parts by weight of the conductiveagent. If the amount of high boiling point solvent is excessively low,effects as a secondary dopant are not adequately obtained, while if theamount of high boiling point solvent added is excessively high, theamount of high boiling point solvent that remains in dry coated filmincreases, thereby resulting in concerns over bleeding (elution)following processing as a laminate and making this undesirable.

Since the aforementioned conductive agent still has inferiordepositability when used alone or as a mixture with a dopant, it ispreferably mixed with film-forming components such polymerizationinitiators or crosslinking agents that activate various types of resincomponents, polymer-forming monomers or oligomers using light or heat toobtain a conductive layer. There are no particular limitations on theseso-called binder components, and are suitably prepared according to thephysical properties of the conductive layer and type of base materialthat forms the conductive layer. Examples of resin components includeacrylic resin, styrene resin, polyester resin, alkyd resin, urethaneresin, amide resin and modified or copolymer resins thereof, whileexamines of monomers and oligomers include polyester (meth)acrylate,urethane (meth)acrylate and epoxy (meth)acrylate. More specifically,examples of radical polymerization types include, but are not limitedto, monofunctional ethyl carbitol (meth)acrylate, phenol ethyleneoxide-modified (meth)acrylate, nonylphenol ethylene oxide-modified(meth)acrylate, ethoxy diethylene glycol acrylate, acryloyl morpholine,isobornyl (meth)acrylate and N-vinylpyrrolidone, bifunctional hexanedioldi(meth)acrylate, hexanediol ethylene oxide-modified diacrylate,neopentyl glycol polyethylene oxide-modified di(meth)acrylate,tetraethylene glycol di(meth)acrylate, tripropylene glycoldi(meth)acrylate, dipropylene glycol di(meth)acrylate, bisphenol Aethylene oxide-modified di(meth)acrylate and polyethylene glycoldi(meth)acrylate, and trifunctional or more highly functionaltrimethylolpropane tri(meth)acrylate, trimethylolpropane ethyleneoxide-modified tri(meth)acrylate, glycerin propoxy tri(meth)acrylate,dipentaerythritol hexaacrylate and ditrimethylolpropane tetraacrylate,while examples of cationic polymerization types include, but are notlimited to, epoxy compounds such as glycidyl ether compounds oralicyclic epoxy compounds, oxetane compounds and vinyl ether compounds.In particular, polyester-based resins can be used preferably.

In addition, a component that imparts solvent resistance to theconductive layer, such as a crosslinking agent or other monofunctionalcomponent, is preferably mixed with the conductive agent as afilm-forming component. Although there are no particular limitations onthe type thereof, examples thereof include the aforementionedtrifunctional or more highly functional monomers and oligomers,organosilanes such as silane coupling agents, and epoxy-based,isocyanate-based or melamine-based crosslinking agents. In particular,silane coupling agents, which have an organic functional group and analkoxyl group in a molecule thereof, can be used preferably since theycontribute to improved sealability of not only the binder component, butalso hard coating layers containing an Si component and PET films havinga highly adhesive layer. On the other hand, caution is requiredregarding the use of melamine-based crosslinking agents since they cancause a decrease in transparency of the conductive layer.

The amount of binder component mixed into the conductive layer ispreferably the minimal amount for demonstrating maximum conductiveperformance of the conductive agent. In addition, in the case ofrequiring patterning of the conductive layer corresponding to the typeof touch panel, the use of a photocurable photosensitive binder ispreferable since it enables the conductive layer to be patterned by aphotomask. Furthermore, in the case of carrying out patterning of theconductive layer by printing, the amount of binder component added(since it has a considerable effect on viscosity) and molecular weightare suitable adjusted in order to adjust to an ink viscosity suitablefor various types of printing methods.

In addition to these main components, additives such as antioxidants,heat resistance stabilizers, ultraviolet absorbers, metal corrosionpreventers, pH adjusters, organic particles, inorganic particles,pigments, dyes, antistatic agents, nucleating agents or coupling agents,or coating assistants such as wetting agents or antifoaming agents, maybe suitably mixed in within a range that does not significantly impairthe conductive performance of the conductive agent.

Wetting agents and antifoaming agents are effective for preventingdefects in the conductive layer, and although silicone-based, long-chainalkyl-based or fluorine-based surfactants and the like are used, sincefluorine-based surfactants require caution since they are susceptible todecreases in sealing durability between the conductive layer and thebase material or anchor layer, silicone-based or long-chain alkyl-basedsurfactants are used preferably. Moreover, in addition to being mixed inas additives, these surface activating components may also be integratedinto the binder resin by copolymerization and the like. Incorporatingthese components to adjust the contact angle of the conductive layer to50 degrees to 100 degrees and more preferably to 60 degrees to 90degrees is preferable since a conductive layer free of defects isobtained while maintaining sealing durability between the conductivelayer and the lower layer.

In addition, various types of conductive agents capable of being coatedby adding to a coating agent may be similarly used in combination withina range that does not impair the performance of the essential componentin the form of the polythiophene-based conductive agent. Examplesthereof include metal compounds such as silver or copper compounds(including fine particles, wires, pastes and soluble salts), metal oxidefine particles such as those of ATO or ITO, organic conductive polymerssuch as polyaniline, and conductive carbon nanotubes.

Although the mixing ratio of conductive substances, including thesevarious types of conductive agents, added to a conductive coatingmaterial is preferably high as previously described, in consideration ofthe balance between depositability and other qualities, the mixing ratiois preferably 10% by weight to 90% by weight and more preferably 30% byweight to 70% by weight.

A conductive layer composed of the components described above preferablyhas high transparency for use in a touch panel and the like. Since thepolythiophene-based conductive agent per se is a colored substance, thetransparency thereof varies considered according to conductiveperformance, and although it also fluctuates depending on thetransparency of the base material and an optical adjustment layer andthe like provided on the surface thereof, total luminous transmittancewhen in the form of a conductive film is preferably 70% or more and morepreferably 88% or more, while haze is preferably 5% or less and morepreferably 2% or less.

Since the optimum value of thickness of the conductive layer can not beuniformly defined since it also varies considerably according to theapplication, type of conductive substance and mixing ratio, it ispreferably 0.01 μm to 1 μm and more preferably 0.02 μm to 0.08 μm. Ifthe dry film thickness is less than 0.01 μm, it becomes difficult toensure uniform conductivity, while if the dry film thickness exceeds 1μm, there is increased susceptibility to decreases in efficiency andincreased costs, thereby making this undesirable.

In order to be used as electrode plates for a touch panel, electricalconductivity of the conductive layer is such that surface resistivity ispreferably 10⁵ Ω/sq or less, and surface resistivity of 10³ Ω/sq or lessis more preferable. This level of surface resistivity can be achievedwith the previously described conductive coating material and coatingamount.

Extracting electrodes may also be formed corresponding to the conditionsof use on the surface of the conductive layer or in a form that enablesconnection therewith. Although highly conductive silver paste or metalmaterials such as aluminum or molybdenum are suitable as materials ofthe extracting electrodes, they are not limited thereto, and a knowntechnique such as sputtering by printing a paste and the like can besuitably used for the formation method thereof.

(Adhesive Layer)

The adhesive layer of the present invention is composed of an adhesivecontaining an acidic component. Although there are no particularlimitations on the components of the adhesive layer, examples ofcomponents used include natural rubber-based adhesives, syntheticrubber-based adhesives, acrylic adhesives, urethane-based adhesives andsilicone-based adhesives. In addition, solvent-type, emulsion-type oraqueous adhesives may also be used. Among these, acrylic adhesives canbe used particularly preferably from the viewpoint of transparency,weather resistance, durability or cost and the like in the case of usingin optical applications.

In particular, a polymer containing as a monomer unit thereof ethylhexylacrylate or butyl acrylate is particularly preferable from the viewpointof adhesive quality.

Furthermore, although various types of organic acids or inorganic acidsmay be used without any particular limitations for the acidic component,in consideration of durability, and particularly bleedout afterincorporating as a member of a device, an acidic group such as acarboxyl group, phosphate group or sulfonate group is preferably boundto a portion of the polymer serving as the main component of theadhesive. Among these, copolymers containing as a monomer unit thereofacrylic acid containing a carboxyl group, or a derivative thereof, arepreferable from the viewpoint of conductive performance as a conductivelaminate.

Other assistants may also be added to the adhesive as necessary.Examples of other assistants include ultraviolet absorbers, thickeners,pH adjusters, tackifiers, binder components, crosslinking agents,adhesive fine particles, antifoaming agents and antiseptic anti-moldagents.

Although the optimum thickness of the adhesive layer cannot be uniformlydefined since it varies according to the composition thereof, is itpreferably 5 μm to 500 μm and more preferably 10 μm to 300 μm. If thethickness is less than 5 μm, the effect of the acidic componentcontained in the adhesive is not adequately obtained, while if thethickness exceeds 500 μm, in addition to increased susceptibility todeformation, there is concern over impairment of location sensingfunction when used as a touch panel, thereby making this undesirable.

(Conductive Laminate)

The polythiophene-based conductive agent used as a conductive substancein the present invention is π-conjugated, organic conductive polymercomposed of a main chain, in which double bonds and single bonds arealternately arranged, that demonstrates efficient conductivity underacidic conditions. Combining this with the adhesive of the presentinvention containing an acidic component is presumed to stabilize theπ-conjugated system of the conductive layer over a long period of timeand thereby improve the durability of electrical conductivity. On theother hand, although adhesives containing an acidic component wereconsidered to be difficult to use in conductive laminates due tocorrosion of the ITO widely used for the conductive layer, theseadhesives have the characteristic of becoming white in response tochanges in the temperature and humidity environment. This whiteningphenomenon was particularly problematic since it has a detrimentaleffect on visibility of a display unit when occurring in the state of apatterned conductive layer incorporated in an image display device. As aresult of combining a polythiophene-based conductive layer and adhesivelayer containing an acidic component, the conductive laminate of thepresent invention employs a configuration capable of maximallydemonstrating the characteristics of both.

However, if the pH of the base material becomes extremely low, there isthe risk of corrosion of peripheral members when incorporating in atouch panel, thereby making this undesirable. Therefore, the surface pHof the conductive layer is preferably 1 to 6 and more preferably 3 to 5.On the other hand, the surface pH of the adhesive layer is preferably 2to 7 and more preferably 3 to 6. In addition, the difference in pHbetween the conductive layer and the adhesive layer is preferably 2 orless. Furthermore, a corrosion preventer may be added to the conductivelayer and adhesive layer as a countermeasure against corrosion, andexamples thereof include 1,2,3-benzotriazole, tolyltriazole andderivatives thereof.

(Base Material)

The conductive layer and the adhesive layer are formed on the surface ofvarious types of base materials in the form of a sheet. The laminatedmay be used as laminate integrated with the base material after havingformed the conductive layer or adhesive layer on the surface of a basematerial, or the conductive layer or adhesive layer may be formed on thesurface of a releasing base material that has been subjected to releasetreatment in advance followed by peeling off the releasing base materialand combining with another base material.

Sheet-like materials such as glass substrates or various types of resinfilms or plates can be used for the base material. These base materialsare selected corresponding to the application. Examples of resinspolyethylene terephthalate, polyethylene naphthalate, polypropyleneterephthalate, polybutylene terephthalate, polypropylene naphthalate,polyethylene, polypropylene, cellophane, diacetyl cellulose, triacetylcellulose, cycloolefin polymers, acetyl cellulose butyrate, polyvinylchloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinylacetate copolymer, polystyrene, polycarbonate, polymethylpentene,polysulfone, polyether ether ketone, polyether sulfone, polyether imide,polyimide, fluorine resin, polyamide, (meth)acrylic resin and copolymersof methyl methacrylate and styrene. In particular, biaxially orientedfilms of polyethylene terephthalate, glass plates, cycloolefin polymersfrom the viewpoints of transparency, weather resistance, solventresistance, rigidity and cost, and polycarbonate sheets having favorabletransparency, can be used preferably.

Various types of additives may be contained in these base materials.Examples of additives include antioxidants, heat resistance stabilizers,ultraviolet absorbers, organic particles, inorganic particles, pigments,dyes, antistatic agents, nucleating agents and coupling agents. Althoughselected corresponding to the required application, these base materialsare preferably transparent materials when using as a touch panel.

Furthermore, various types of layers may be provided on the surface ofeach type of base material corresponding to the application. Examples ofsuch layers include optical adjustment layers such as an interferencefringe countermeasure layer or dispersion adjustment layer containingvarious types of dispersants, and an anchor layer containing anisocyanate or other reactive substance for the purpose of enhancingsealability with the upper layer. In addition, uneven surface treatmentsuch as sandblasting treatment or solvent treatment, or surfaceoxidation treatment such as corona discharge treatment, chromic acidtreatment, flame treatment, hot air treatment or ozone-ultravioletirradiation treatment may also be carried out. Furthermore, a foamreleasing layer may also be provided for patterning the conductive layerthat enables separation of only locations on the conductive layer basematerial that have been irradiated with an active energy beam. Inaddition, a hard coating layer containing hard components may beprovided on the surface of the base material in the case the basematerial surface is exposed or in order to inhibit superficial abrasionsfrom occurring in the base material during processing.

In the case of providing a hard coating layer, an acrylic polymer can bepreferably used for the main component thereof. Acrylic polymers arepolymers of monomers or oligomers having polymerizable unsaturatedgroups.

Polyfunctional (meth)acrylates are preferable as monomers or oligomersof organic compounds having polymerizable unsaturated groups, examplesof which include bifunctional (meth)acrylates such as dipropylene glycoldi(meth)acrylate, 1,6-hexanediol di(meth)acrylate, tripropylene glycoldi(meth)acrylate, polyethylene glycol (weight average molecular weight:600) di(meth)acrylate, propylene oxide-modified neopentyl glycoldi(meth)acrylate, modified bisphenol A di(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate or polyethylene glycol (weight averagemolecular weight: 400) di(meth)acrylate, trifunctional (meth)acrylatessuch as pentaerythritol (meth)acrylate, trimethylolpropanetri(meth)acrylate, trimethylolpropane ethoxy tri(meth)acrylate,polyether tri(meth)acrylate or glycerol propoxy tri(meth)acrylate, andtetrafunctional or more highly functional (meth)acrylates such aspentaerythritol tetra(meth)acrylate, pentaerythritol ethoxytetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, propionicacid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritolmonohydroxy penta(meth)acrylate or dipentaerythritol hexa(meth)acrylate.One type of these polyfunctional acrylates may be used alone or two ormore types can be used in combination.

Tetrafunctional or more highly functional (meth)acrylates are selectedmore preferably in order to obtain pencil hardness of the resulting hardcoated layer of 3H or higher.

Monomers or oligomers of organic compounds having polymerizableunsaturated groups may be able to be cured by heating or with an activeenergy beam.

A flexible component may also be contained in the hard coating layer.The containing of a flexible component makes it possible to prevent theformation of cracks when stamping out the conductive laminate.

(Meth)acrylates having one or more polymerizable unsaturated groups in amolecule thereof are used for the flexible component. Examples of theaforementioned (meth)acrylates include bifunctional (meth)acrylates suchas tricyclodecane methylol di(meth)acrylate, ethylene oxide-modifieddi(meth)acrylates of bisphenol F, ethylene oxide-modifieddi(meth)acrylates of bisphenol A, ethylene oxide-modifieddi(meth)acrylates of isocyanuric acid, polypropylene glycoldi(meth)acrylate or polyethylene glycol di(meth)acrylate, trifunctional(meth)acrylates such as trimethylolpropane tri(meth)acrylate, propyleneoxide-modified tri(meth)acrylates of trimethylpropane or ethyleneoxide-modified tri(meth)acrylates of trimethylpropane, urethane(meth)acrylates, polyester (meth)acrylates and polyether(meth)acrylates. In particular, trifunctional (meth)acrylates andurethane (meth)acrylates are selected more preferably.

One type of these (meth)acrylates can be used alone or two or more typescan be used in combination.

The hard component may contain reactive inorganic oxide particles and/orreactive organic particles. Containing reactive inorganic oxideparticles and/or reactive organic particles is particularly preferablesince they are able to impart soiling resistance, anti-fingerprintproperties, antistatic properties and the like.

Reactive inorganic oxide particles are inorganic oxide particles thathave been treated with a coupling agent, while reactive organicparticles are organic particles that have been treated with a couplingagent. Treatment of inorganic oxide particles or organic particles witha coupling agent makes it possible to enhance bonding strength withacrylic polymers. As a result, surface hardness and scratch resistancecan be improved, and dispersibility of the inorganic oxide particles andorganic particles can also be improved.

Here, the inorganic oxide particles preferably have high hardness, andexamples of inorganic oxide particles that can be used include silicondioxide particles, titanium dioxide particles, zirconium oxide particlesand aluminum oxide particles.

Examples of organic particles that can be used include resin particlessuch as those of acrylic resin, polystyrene, polysiloxane, melamineresin, benzoguanamine resin, polytetrafluoroethylene, cellulose acetate,polycarbonate or polyamide.

Examples of coupling agents include γ-aminopropyltriethoxysilane,γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane,γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane,γ-aminopropyltriethoxysilane and γ-aminopropyl-triethoxyaluminum. Onetype of these coupling agents may be used alone or two or more types beused in combination.

The amount of coupling agent used for treatment is preferably 0.1 partsby weight to 20 parts by weight and more preferably 1 part by weight to10 parts by weight to 100 parts by weight of inorganic oxide particlesor organic particles.

In addition, various types of releasing sheets, in which a releasingtreatment layer is formed on various types of base materials aspreviously described or a sheet-like material such as paper with acondensed or addition type silicone-based releasing agent, orolefin-based, long-chain alkyl group-containing polymer-based orfluorine-based non-silicone-based releasing agent, can be used as areleasing base material used as a temporary base material of theadhesive layer. A resin film made of polyester or polypropylene, or apaper sheet, can be used particularly preferable from the viewpoints ofphysical properties and cost.

(Laminate Preparation Method)

The conductive laminate 1 of the present invention can be manufacturedin, for example, the manner described below.

(1) Conductive Layer Formation Step

A conductive layer 12 is formed on one side of a first base material 11to obtain a conductive film 10. In the case the conductive layer 12requires patterning or extracting electrodes 32, extraction processingmay be carried out at this time. A cross-sectional view of an embodimentof the conductive film 10 is shown in FIG. 2. Furthermore, in FIG. 2,the same reference symbols are used to indicate those constituentmembers that are same as those in FIG. 1, and detailed explanationsthereof are omitted. Furthermore, this applies similarly to subsequentdrawings as well.

(2) Adhesive Layer Formation Step

A liquid adhesive is coated onto one side of a first releasing basematerial 22 and dried to form an adhesive layer 21, and a secondreleasing base material 23 is affixed to the surface thereof to obtainan adhesive sheet 20. A cross-sectional view of an embodiment of theadhesive sheet 20 is shown in FIG. 3.

(3) Adhesion Step

An adhesive layer surface obtained by peeling off the second releasingbase material 23 of the adhesive sheet 20 is adhered to the conductivelayer side of the conductive film 10 to obtain the conductive laminate1.

(4) Cutting or Stamping Step

The conductive laminate 1 is then cut or stamped to process into adesired form.

In the aforementioned conductive layer formation step (1) and theadhesive layer formation step (2), the conductive layer, adhesive layeror layer such as an anchor layer formed as necessary are formed by knownmeans such as coating or printing.

Examples of coating methods include, but are not limited to, bladecoating, air knife coating, roll coating, bar coating, gravure coating,microgravure coating, rod and blade coating, lip coating, die coatingand curtain coating. Examples of printing methods include, but are notlimited to, screen printing, offset printing, flexographic printing,gravure offset printing and inkjet printing.

Microgravure coating is preferable for the conductive layer and anchorlayer since the coated amount is comparatively small, while lip coatingand die coating can be preferably used for applying to the adhesivelayer. In addition, in cases requiring patterning, the conductive layermay be formed only at those locations where required by gravure coatingor various types of printing methods, or unnecessary portions of theconductive layer may be removed by a known wet or dry etching method(such as by ablation using laser light) after having formed a uniformconductive layer in advance. In the case of carrying out wet etching,etching treatment may be carried out after masking a portion of theconductive layer by photolithography or screen printing using varioustypes of active energy beams, and an etching solution for organicconductive polymers described in Japanese Patent Application Laid-OpenNos. 2008-091487 or 2008-115310 can be preferably used for thistreatment. In addition, etching treatment may also be carried outwithout masking by directly printing onto a portion of the conductivelayer to be removed an etching paste in the manner of IsishapeHiperEtch® manufactured by Germany's Merck KGaA.

Furthermore, the active components of each layer may be diluted withvarious types of solvents in order to prepare a solvent or ink optimalfor layer formation. Examples of solvents include water, methanol,ethanol, isopropanol, acetone, methyl ethyl ketone, toluene, n-hexane,n-butyl alcohol, methyl isobutyl ketone, methyl butyl ketone, ethylbutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, propyleneglycol monomethyl ether acetate, ethylene glycol monoethyl ether,propylene glycol monomethyl ether and N-methyl-2-pyrrolidone. One typeof these solvents may be used alone or two or more types may be used asa mixture. Solvents having different evaporation rates are usedpreferably in order to reduce coating unevenness. For example, mixturesof methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butylacetate and propylene glycol monomethyl ether are used preferably.

In addition, in order to enhance durability of the coating layerobtained after drying, components may be added that accelerate curing ofthe coating liquid or ink used to form each layer. In the case of usinga heat-curable crosslinking agent such as an isocyanate compound orepoxy compound, crosslinking of the coated film may be accelerated andcoated film strength may be improved by carrying out heat treatment whendrying the coated film or in a chamber using a heating oven or infraredlamp.

On the other hand, in the case of having added a knownphotopolymerization initiator or photosensitive resin and the like, themolecular weight of the coated film may be increased or the coated filmstrength may be improved by accelerating the crosslinking reaction byirradiating with an active energy beam.

Examples of active energy beams include ultraviolet light and anelectron beam, and ultraviolet light is particularly preferable from theviewpoint of versatility. Examples of light sources of ultraviolet lightthat can be used include high-pressure mercury lamps, low-pressuremercury lamps, ultra-high-pressure mercury lamps, metal halide lamps,carbon arc lamps, xenon lamps and electrode-less ultraviolet lamps.

Examples of electron beams that can be used include electron beamsradiated from various types of electron accelerators such as aCockcroft-Walton accelerator, Van de Graff accelerator, resonancetransformer accelerator, insulated core transformer accelerator, linearaccelerator, dynamitron accelerator or high-frequency accelerator.

Curing by irradiating with an active energy beam is preferably carriedout in the presence of an inert gas such as nitrogen in order to avoidinhibition of curing caused by oxygen in the atmosphere, and nitrogengas can be used preferably from the viewpoint of cost.

In addition, the active energy beam irradiation step may be carried outby dividing into two stages consisting of a preliminary curing step anda final curing step.

Formation of the conductive laminate 1 may also be carried out by thefollowing procedures in addition to the procedures described above.

(a) A liquid adhesive is coated directly onto the side of the conductivelayer 12 in the conductive film 10 and dried to form the adhesive layer21, followed by adhering the first releasing base material 22.

(b) A liquid adhesive is coated onto one side of the first releasingbase material 22 and dried to form the adhesive layer 21, followed byadhering the side of the conductive layer 12 of the conductive film 10thereto.

There are no particular limitations on the base material or releasingbase material combined with the conductive layer and adhesive layer, andeach layer may be coated directly onto other members used instead of theaforementioned base materials, such as a polarizing plate used in liquidcrystal modules.

In order to improve coatability of the conductive layer and adhesivelayer, the coating solution may be diluted with solvent as necessary.Examples of solvents include alcohols (such as methanol, ethanol orpropanol), ketones (such as acetone or methyl ethyl ketone), and ethers(such as diethyl ether, methyl cellosolve or ethyl cellosolve).

Examples of coaters used for coating include a blade coater, air knifecoater, roll coater, bar coater, gravure coater, rod and blade coater,lip coater, die coater, curtain coater and printing machines.

Drying is carried out with a hot forced air dryer or vacuum dryer andthe like.

In addition, instead of forming the adhesive layer with a liquidadhesive, double-sided adhesive tape may also be used. Double-sidedadhesive tape is provided with an adhesive layer between a pair ofreleasing sheets. Some adhesive layers contain a base material whileother are composed of adhesive only. Furthermore, there are noparticular limitations on this base material or adhesive sheet, knownmaterials can be used, and examples thereof include paper and film. Thereleasing sheets are preferably single-sided releasing sheets having areleasing layer on one side.

In addition, the peel strength of one of the releasing sheets withrespect to the adhesive layer is preferably different from the peelstrength of the other releasing sheet with respect to the adhesivelayer. This facilitates release of one of the releasing sheets prior torelease of the other releasing sheet.

Although the cutting or stamping step (4) is carried out afterlaminating each of the sheet members that compose the conductivelaminate 1, this may be carried out prior to lamination corresponding tothe required form of the members.

[Touch Panel]

Although the conductive laminate of the present invention can be used asa constituent member of various types of touch panels, it isparticularly preferable as an essential member of a projective touchpanel of an electrostatic capacitive type in which a transparentconductive layer patterned in a form having regularity in a uniaxialdirection is arranged on both sides of an insulating layer by making thepatterns of the conductive layer to be intersecting perpendicularly.Touch panels employing this method have a configuration in whichconductive layers located on both sides of an insulating layer arelaminated to other members with adhesive. Although examples of theinsulating layer include various types of sheet base materials andadhesive layers, there are no particular limitations thereon, and forexample, the insulating layer consists of a sheet base material,adhesive layer and sheet base material in that order in the case oflaminating the base material sides of two conductive films having aconductive layer on one side thereof with an adhesive. Consequently, useof the conductive laminate of the present invention makes it possible tomanufacture a touch panel that not only easily inhibits changes inperformance even in harsh environments subjected to high temperature orhigh humidity and the like, but also has superior shock resistance andis free of the occurrence of whitening phenomenon during sudden changesin temperature and humidity. Although a projective touch panel 100 of anelectrostatic capacitive type according to an embodiment of the presentinvention is shown in FIG. 4, since touch panel configuration variesconsiderably for each manufacturer and type, the configuration is notlimited thereto.

In the configuration shown in FIG. 4, conductive layers 12-U (upperelectrode) and 12-L (lower electrode), which have been patterned into aform having regularity in the uniaxial direction, are arranged on bothsides of the base material 11 so that the patterns of the conductivelayers intersect perpendicularly, and adhesive layers 21-U and 21-L arelaminated on both sides thereof so as to be in direct contact with theconductive layers. Moreover, a covering base material 101 is laminatedon one of the outsides thereof, while the polarizing plate side of aliquid crystal module 102 is laminated on the other side. Furthermore,the conductive layers are connected to an extracting electrode layer 103and an FPC connector 104. Moreover, the conductive layers areelectrically connected to an electrostatic capacitance detection circuit105 with a flexible printed circuit board (abbreviated as FPC) and thelike to complete the touch panel 100.

EXAMPLES

Although the following provides a more detailed explanation of thepresent invention by listing examples thereof, the present invention isnaturally not limited thereto. Furthermore, the term “%” used in theexamples indicates percent by weight unless specifically indicatedotherwise.

Example 1 Production of Conductive Film

An aqueous dispersion containing a conductive substance obtained bypolymerizing 3,4-ethylenedioxythiophene in the presence of polystyrenesulfonate (abbreviated as PEDOT-PSS) was mixed with a binder componentin the form polyester resin (Vylonal MD1200, Toyobo Co., Ltd.) and afluorine-based surfactant (Megafac F-556, DIC Corp.) at a ratio of 1:1:1as the solid fraction, followed by diluting with methanol to obtain amixture A having a solid concentration of 1%. This dispersion was thenmixed with a 1% solution of a silane coupling agent (KBM-403, Shin-EtsuSilicone Co., Ltd.), obtained by diluting with a 50/50 mixture of waterand methanol, at a weight ratio of 100:30 to prepare a conductivecoating agent A. This conductive coating agent A was coated onto oneside of a first base material in the form of a biaxially orientedpolyethylene terephthalate film provided with a surface-treated highlyadhesive layer on both sides thereof (trade name: Cosmoshine A4300,Toyobo Co., Ltd., thickness: 100 μm) to a dry thickness of about 0.2 μmwith a bar coater followed by drying to obtain a conductive film 1having surface resistivity of 287 Ω/sq (as determined in compliance withJIS-K 7194) and total luminous transmittance of 88.3% (as determined incompliance with JIS-K 7105).

Next, a conductive layer was also similarly formed on the other side toobtain a double-sided conductive film 1 for use in touch panelevaluation.

(Production of Adhesive Sheet)

<Preparation of Adhesive Containing Acidic Component)

After sealing nitrogen gas in a reaction apparatus equipped with astirrer, thermometer, reflux condenser, dropping device and nitrogeninlet tube, solvents consisting of ethyl acetate and acetone were added.Next, monomer components consisting of 80 parts of ethylhexyl acrylate,20 parts of methyl acrylate and 2 parts of acrylic acid and 0.08 partsof a polymerization initiator in the form of benzoyl peroxide were addedto the reaction apparatus followed by polymerizing for 8 hours at thesolvent reflux temperature in flowing nitrogen gas while stirring.Following completion of the polymerization reaction, toluene was addedto obtain an acrylic polymer.

Next, 0.08 parts of 4,6-bis(octylthiomethyl)-o-cresol (trade name:Irganox 1520L, Ciba Specialty Chemicals Corp.) were added to the acrylicpolymer to obtain a primary adhesive, followed by mixing 0.2 parts of acrosslinking adhesive in the form of tertiary amine group-containingepoxy resin to 100 parts as solid of the primary adhesive to obtain anadhesive A.

<Production of Adhesive Sheet>

The aforementioned adhesive was coated onto a PET releasing film havinga thickness of 38 μm used as a first releasing base material (tradename: 38RL07(5), Oji Specialty Paper Co., Ltd.) so that the coatedamount of the adhesive after drying was 175 g/m², followed by drying for5 minutes at 100° C. to form an adhesive layer on the PET releasing filmserving as the first releasing base material. Next, a PET releasingfilm, having a thickness of 38 μm and subjected to mold releasetreatment set so that peel strength was less than that of the firstreleasing base material (trade name: 38RL07(2), Oji Specialty Paper Co.,Ltd.) was laminated onto the surface of the adhesive layer to serve as asecond releasing base material, followed by allowing to stand for 1 weekat room temperature to obtain an adhesive sheet A composed of a layercomposition consisting of a first releasing base material, an adhesivelayer and a second releasing base material.

(Production of Conductive Laminate)

The second releasing base material of adhesive sheet A was peeled off,the adhesive surface thereof was affixed to the surface of the secondbase material composed of the same PET film as the first base material,and the resulting laminate was cut to a size of 2 cm×9 cm. Next, anextracting electrode was formed on both ends of the conductive film 1cut to a size of 2 cm×10 cm with silver paste (Dotite FA-401CA, FujikuraKasei Co., Ltd.). Moreover, the adhesive surface of the adhesive sheet Afrom which the first releasing base material had been peeled off wasaffixed to the surface thereof followed by carrying out autoclavingtreatment for 30 minutes under conditions of 50° C. and 0.8 Pa to obtaina conductive laminate 1 of Example 1 composed of a layer compositionconsisting of a first base material, a conductive layer, an adhesivelayer and a second base material. A cross-sectional view of theresulting conductive laminate 1 is shown in FIG. 5, while an overheadview is shown in FIG. 6.

<Production of Liquid Crystal Module with Touch Panel>

A photoresist dry film was affixed to the conductive layer of thedouble-sided conductive film 1, a quartz mask was superimposed thereon,and both sides were subjected to treatment consisting of irradiatingeach side with ultraviolet light at an exposure dose of 300 mJ/cm² witha metal halide lamp (Ultraviolet Curing Multi-Metal Lamp M03-L31, EyeGraphics Co., Ltd.). The quartz mask was patterned in a shape such thatthe X and Y electrode patterns were arranged so as to intersectperpendicularly on both sides of the first base material to enabledetection of location when used as a touch panel sensor. Since theultraviolet exposure dose used here was such that the dosage ofultraviolet light that reached the coated surface on the opposite sideof the first base material by passing there through is extremely low,the pattern on the opposite side was not transferred to the back.Continuing, after removing a portion of the conductive layer togetherwith uncured resist using an etching solution for use with organicpolymer-type conductive layers, the remainder of the resist film waspeeled off to obtain a double-sided, patterned conductive film 1.

(Production of Liquid Crystal Module with Touch Panel)

After forming extracting electrodes around the periphery of thedouble-sided, patterned conductive film 1 using the silver pastedescribed above, the electrodes were connected to an FPC connector.Continuing, the polarizing plate side of a liquid crystal module wasaffixed to one side while a covering member in the form of optical glasshaving a thickness of 1 mm was affixed to the other side with the twoadhesive sheets A interposed there between to produce a liquid crystalmodule 1 provided with a touch panel having the same configuration asthat shown in FIG. 1.

Example 2

A double-sided conductive film 2 having a total luminous transmittanceof 88.6% was produced by adjusting the thickness of the conductive layerso as to obtain surface resistivity of 287 Ω/sq in the same manner asExample 1 with the exception of using a silicone-based surfactant(Leveling Agent KP-110, Shin-Etsu Silicone Co., Ltd.) as a conductivecoating agent B instead of the fluorine-based surfactant, and aconductive laminate 2 and a liquid crystal module 2 provided with atouch panel were produced using this double-sided conductive film 2.

Example 3

A double-sided conductive film 3 having a total luminous transmittanceof 88.0% was produced by adjusting the thickness of the conductive layerso as to obtain surface resistivity of 287 Ω/sq in the same manner asExample 2 with the exception of mixing a mixture B, a 1% solutionobtained by diluting a silane coupling agent (KBM-403, Shin-EtsuSilicone Co., Ltd.) with methanol, and a 1% solution obtained bydiluting a melamine-based crosslinking agent (Sumimarl M-50W, SumitomoChemical Co., Ltd.) with methanol, at ratio of 100:15:15 for use as aconductive coating agent C, and a conductive laminate 3 and a liquidcrystal module 3 provided with a touch panel were produced using thisdouble-sided conductive film 3.

Example 4

After coating a hard coating agent (Aicatron Z711, Aica Inc., solidconcentration: 40%) onto both sides of a biaxially oriented polyethyleneterephthalate film provided with a surface-treated highly adhesive layeron both sides thereof (trade name: Lumilar U48, Toray Industries, Inc.,thickness: 50 μm) to a dry thickness of 4 μm with a bar coater, thecoated film was dried with hot air at 80° C. to form a hard coatinglayer by irradiating with ultraviolet light at 300 mJ/cm².

A conductive film 4 and a double-sided conductive film 4 having surfaceresistivity of 287 Ω/sq and total luminous transmittance of 89.2% wereproduced in the same manner as Example 2 with the exception of usingthis hard coating layer for the first base material of the conductivefilm, and these were then used to obtain a conductive laminate 4 and aliquid crystal module 4 provided with a touch panel.

Example 5

A conductive film 5 and a double-sided conductive film 5 having surfaceresistivity of 287 Ω/sq and total luminous transmittance of 89.1% wereproduced in the same manner as Example 1 with the exception of using apolycarbonate film (trade name: R40-#140, Kaneka Corp., thickness: 40μm) for the first base material and using a mixture of Denatron PT-200MF(Nagase Chemtex Corp., ratio of primary agent to crosslinking agent todiluent=100:2:51) as a conductive coating agent D, and these were thenused to obtain a conductive laminate 5 and a liquid crystal module 5provided with a touch panel.

Example 6

A conductive film 6 and a double-sided conductive film 6 having surfaceresistivity of 287 Ω/sq and total luminous transmittance of 88.8% wereproduced in the same manner as Example 2 with the exception of using acycloolefin polymer film (trade name: Zeonor ZF14, Zeon Corp.,thickness: 100 μm) for the first base material, and these were then usedto obtain a conductive laminate 6 and a liquid crystal module 6 providedwith a touch panel.

Example 7

A conductive film 7 and a double-sided conductive film 7 having surfaceresistivity of 287 Ω/sq and total luminous transmittance of 89.1% wereproduced in the same manner as Example 4 with the exception of using afilm provided with a hard coating layer on both sides of a biaxiallyoriented polyethylene terephthalate film provided with a surface-treatedhighly adhesive layer on both sides thereof (trade name: Lumilar U46,Toray Industries, Inc., thickness: 188 μm) for the first base material,and these were then used to obtain a conductive laminate 7.

A liquid crystal module 7 provided with a touch panel was obtained inthe same manner as Example 1 with the exception of patterning theconductive layers on both sides of a double-sided conductive film 7 bylaser processing instead of by etching.

Example 8

An adhesive sheet B was produced using an adhesive B synthesized in thesame manner as Example 1 with the exception of using butyl acrylateinstead of ethylhexyl acrylate and using styrene sulfonate instead ofacrylic acid, and the conductive film 7 and double-sided conductive film7 of Example 7 were combined to obtain a conductive laminate 8 and aliquid crystal module 8 provided with a touch panel.

Example 9

A conductive film 9 and a double-sided conductive film 9 having totalluminous transmittance of 90.7% were produced in the same manner asExample 7 with the exception of adjusting the thickness of theconductive layer to surface resistivity of 450 Ω/sq, and these were thenused to obtain a conductive laminate 9 and a liquid crystal module 9provided with a touch panel.

Example 10

An adhesive sheet C was produced using an adhesive C synthesized in thesame manner as Example 1 with the exception of using vinyl phosphateinstead of acrylic acid, and the conductive film 9 and double-sidedconductive film 9 of Example 9 were combined to obtain a conductivelaminate 10 and a liquid crystal module 10 provided with a touch panel.

Example 11

Conductive glass having surface resistivity of 450 Ω/sq and totalluminous transmittance of 87.9% was produced in the same manner asExample 1 with the exception of using an optical reinforced glass platehaving a thickness of 1 mm for the first base material, and forming aconductive layer by solid printing using a conductive ink E containingPEDOT-PSS by screen printing, and a conductive laminate 11 was obtainedusing this instead of a conductive film.

Continuing, a double-sided, patterned conductive layer was produced bypattern printing the aforementioned conductive ink E onto both sides ofthe first base material by screen printing instead of patterning byetching the conductive layer. A liquid crystal module 11 provided with atouch panel was then obtained in the same manner as Example 1 with theexception of using this double-sided, pattern conductive layer.

Example 12

A conductive film 12 and a double-sided, patterned conductive film 12having surface resistivity of 450 Ω/sq and total luminous transmittanceof 88.2% were produced in the same manner as Example 11 with theexception of printing a conductive ink F containing PEDOT-PSS onto thesame first base material as Example 7 by gravure offset printing insteadof by screen printing, and a conductive laminate 12 and a liquid crystalmodule 12 provided with a touch panel were obtained in the same manneras Example 1 with the exception of using these conductive films 12.

Example 13

A conductive film 13 having surface resistivity of 450 Ω/sq and totalluminous transmittance of 88.1% was produced by coating OJE-1 (ArakawaChemical Industries, Ltd.) onto the same first base material as Example7 as an ultraviolet-curable conductive coating agent G containing aconductive substance in the form of PEDOT-PSS, drying the coated basematerial, and irradiating with ultraviolet light at an exposure dose of500 mJ/cm², and a conductive laminate 13 was obtained in the same manneras Example 1 with the exception of using conductive film 13.

<Production of Liquid Crystal Module with Touch Panel>

A double-sided, patterned conductive film 13 was produced in the samemanner as Example 1 with the exception of coating OJE-1 on both sides ofthe same first base material with a bar coater, followed by drying,superimposing a quartz mask, irradiating with ultraviolet light at anexposure dose of 500 mJ/cm² and rinsing with water, and this was thenused to obtain a liquid crystal module 13 provided with a touch panel.

Example 14 Production of Anchor Layer

An anchor layer coating material A, obtained by mixing Takenate D-110N(Mitsui Chemicals Polyurethanes Inc.) (1 part) and Mowital B60HH(Kuraray Co., Ltd.) (9 parts) and diluting to a non-volatile componentcontent of 9.0% by weight with 2-butanone (methyl ethyl ketone), wascoated onto both sides of the biaxially oriented polyethyleneterephthalate film having a thickness of 188 μm and provided with asurface-treated highly adhesive layer used in Example 7 to a dry weightof 0.7 g/m² with a bar coater followed by drying (1 minute at 130° C.)to form an anchor layer.

(Production of Foam Releasing Layer)

The composition of a foam releasing layer was obtained by mixing acopolymer (100 parts by weight) of degradable compounds in the form oftert-butyl methacrylate (38 mol %), methyl methacrylate (36 mol %),2-hydroxyethyl methacrylate (20 mol %) and n-butyl methacrylate (6 mol%) with an acid generator in the form of an oniom salt-based acidgenerator consisting of2-[2,2,3,3,4,4,5,5-octafluoro-1-(nonafluorobutyl-sulfonyloxyimino)-pentyl]-fluorene(CGI-1907, Ciba Japan K.K.) (0.5 parts), followed by diluting with ethylacetate to obtain a foam releasing layer coating material having anon-volatile component content of 25.0% by weight. Next, the foamreleasing layer coating material was coated onto the surfaces (bothsides) of an anchor layer formed on a base material using an applicablebar having a gap of 160 μm (doctor blade, Yoshimitsu Seiki Co., Ltd.) toa dry weight of 20 g/m² followed by drying (8 minutes at 105° C.) toobtain a base material for patterning.

(Production of Conductive Layer)

A conductive film 14 and a double-sided conductive film 14 havingsurface resistivity of 450 Ω/sq and total luminous transmittance of88.1% were produced by forming a conductive layer with a bar coater inthe same manner as Example 2 with the exception of using this basematerial for patterning for the first base material to obtain aconductive laminate 14.

<Production of Liquid Crystal Module with Touch Panel>

(Releasing Adhesive Film Lamination Step)

The releasing adhesive film used was produced according to the methoddescribed below. A PET film G2 manufactured by Teijin Dupont FilmsJapan, Ltd. (thickness: 75 μm) was used as a support. Adhesivecomponents consisting of 100 parts by weight of a primary agent in theform of SH101 (Toyo Ink Co., Ltd., 60%) and 2 parts by weight of acuring agent in the form of BXX6105 (Toyo Ink Co., Ltd., 37.5%) weremixed to obtain a releasing adhesive. Next, the releasing adhesive wascoated onto the PET film G2 using the aforementioned applicator having agap of 100 μm followed by drying (2 minutes at 100° C.) and allowing tostand for 1 week at room temperature to obtain a releasing adhesivefilm. The thickness of the releasing adhesive layer was 12 μm. Theproduced adhesive film was laminated onto the surfaces (both sides) ofthe aforementioned conductive layer using a laminator.

(Ultraviolet Irradiation Step)

A mask pattern was exposed to ultraviolet light by irradiating at 300mJ/cm² using a vacuum exposure system while adhering to the side of thebase material of the adhesive film.

(Heating Step)

Continuing, the aforementioned sheet was subjected to heat treatment for2 minutes in a constant temperature dryer at 130° C. Only the foamreleasing layer of the irradiated pattern foamed and peeled off easily.

(Adhesive Film Removal Step)

Treatment enabling the releasing adhesive film to peel from the producedlaminate and only the portion caused by foam by ultraviolet irradiationto peel for each conductive layer was carried out on both sides toobtain a double-sided, patterned conductive film 14. A liquid crystalmodule 14 provided with a touch panel was then produced in the samemanner as Example 1 with the exception of using this double-sided,patterned conductive film 14.

Comparative Example 1 Preparation of Adhesive Not Containing AcidicComponent

After sealing nitrogen gas in a reaction apparatus equipped with astirrer, thermometer, reflux condenser, dropping device and nitrogeninlet tube, solvents consisting of ethyl acetate and acetone were added.Next, monomer components consisting of 78 parts of 2-methoxyethylacrylate, 20 parts of ethylhexyl acrylate, 2 parts of 4-hydroxybutylacrylate and 0.2 parts of a polymerization initiator in the form of2,2-azobisisobutyronitrile were added to the reaction apparatus followedby polymerizing for 8 hours at 65° C. in flowing nitrogen gas whilestirring. Following completion of the polymerization reaction, toluenewas added to obtain an adhesive D.

A conductive laminate 15 and a liquid crystal module 15 provided with atouch panel were produced in the same manner as Example 2 with theexception of using an adhesive sheet D obtained from the adhesive Dinstead of the adhesive sheet A.

Comparative Example 2

A conductive laminate 16 was produced in the same manner as Example 1with the exception of using a PET film having a thickness of 175 μminstead of the conductive film 1, and using an ITO film having surfaceresistivity of 450 Ω/sq and total luminous transmittance of 89.2% onwhich an amorphous ITO layer was formed by sputtering.

In addition, a double-sided, patterned conductive film 16 was producedin the same manner as Example 1 with the exception of patterning adouble-sided ITO film having an ITO layer on both sides in the samemanner as described above using an ITO etching solution, and this wasused to produce a liquid crystal module 16 provided with a touch panel.

Comparative Example 3

A conductive laminate 17 and a liquid crystal module 17 provided with atouch panel were produced in the same manner as Comparative Example 2with the exception of using the adhesive sheet D used in ComparativeExample 1 instead of the adhesive sheet A.

Comparative Example 4

A conductive laminate 18 was produced in the same manner as ComparativeExample 3 with the exception of using a PET film having a thickness of125 μm instead of the ITO film 1, and using an ITO film 2 having surfaceresistivity of 274 Ω/sq and total luminous transmittance of 88.1% onwhich an amorphous ITO layer was formed by sputtering.

In addition, a double-sided, patterned conductive film 18 was producedin the same manner as Comparative Example 3 with the exception of usinga double-sided ITO film 2 having an ITO layer on both sides in the samemanner as previously described, and this was used to produce a liquidcrystal module 18 provided with a touch panel.

Comparative Example 5

A conductive laminate 19 was produced in the same manner as ComparativeExample 3 with the exception of using a PET film having a thickness of50 μm instead of the ITO film 1, and using an ITO film 3 having surfaceresistivity of 306 Ω/sq and total luminous transmittance of 89.3% thatwas crystallized by subjecting to heat treatment for 1 hour at 150° C.and on which an ITO layer was formed by sputtering.

In addition, a double-sided, patterned conductive film 19 and a liquidcrystal module 19 provided with a touch panel were produced in the samemanner as Comparative Example 3 with the exception of using adouble-sided ITO film 3 having an ITO layer on both sides in the samemanner as previously described.

Comparative Example 6

A conductive laminate 20 and a liquid crystal module 20 provided with atouch panel were produced in the same manner as Comparative Example 1with the exception of using the conductive film 12 and double-sided,patterned conductive film used in Example 12.

(Evaluation Methods)

Each of the conductive laminates and liquid crystal modules providedwith touch panels obtained in Examples 1 to 14 and Comparative Examples1 to 6 were evaluated for quality using the methods described below.

(Evaluation of Conductive Laminate Durability)

Two sets of three test pieces each of the conductive laminates wereproduced, and resistance between electrodes formed on both ends of eachtest piece was measured with an ohmmeter in a normal temperature, normalhumidity environment (23° C., 50% RH). Next, one set of test pieces wasleft in the normal temperature, normal humidity environment (23° C., 50%RH), and the other set was transferred to a high temperature, highhumidity environment (85° C., 80% RH) and allowed to stand in order tocarry out a durability test. After 250 hours, the test piecestransferred to the high temperature, high humidity environment werereturned to the normal temperature, normal humidity environment followedby observation of their appearance. After humidifying for 2 hours underthese conditions, the resistance values of the test pieces were measuredand evaluated according to the following criteria.

[Observation of Appearance]

A: Hardly any change, favorable appearance

B: Although test piece whitened somewhat after transferring from hightemperature, high humidity environment to normal temperature, normalhumidity environment, whitening became inconspicuous within 30 minutes

C: Test piece whitened after transferring from high temperature, highhumidity environment to normal temperature, normal humidity environment,and the clouded state persisted for several hours.

[Changes in Resistance Values]

A: Change in electrical resistance before and after durability testextremely favorable at less than 10%

B: Change in electrical resistance before and after durability testfavorable at 10% to less than 20%

C: Change in electrical resistance before and after durability test 20%to less than 100%

D: Change in electrical resistance before and after durability testunsuitable at 100% or more

(Evaluation of Conductive Laminate Bendability)

One set of three test pieces each of the conductive laminates wereproduced, and resistance between electrodes formed on both ends of eachtest piece was measured with an ohmmeter in a normal temperature, normalhumidity environment (23° C., 50% RH). Next, a bendability test wascarried out by employing a procedure consisting of repeatedly bendingthe test pieces around a cylinder having a diameter of 5 mm as shown inFIG. 7 20 times in each direction, followed by observing the appearanceof the test pieces and measuring the resistance values thereof.Fluctuations in resistance values were evaluated according to thecriteria indicated below.

[Observation of Appearance]

A: No change, favorable appearance

B: Slight damage to a portion of the laminate surface

C: Separation marks observed over a portion or all of the laminate,unsuitable appearance

[Changes in Resistance Values]

A: Change in electrical resistance before and after durability testfavorable at less than 10%

B: Change in electrical resistance before and after durability test at10% to less than 100%

C: Change in electrical resistance before and after durability testunsuitable at 100% or more

(Evaluation of Use as Touch Panel)

The touch panels obtained in Examples 1 to 14 and Comparative Examples 1to 6 were held for 250 hours in two types of environments consisting ofa normal temperature, normal humidity environment (23° C., 50% RH) andhigh temperature, high humidity environment (85° C., 80% RH), followedby confirming operation in the normal temperature, normal humidityenvironment and evaluating according to the criteria indicated below.The evaluation results are shown in Table 2.

[Responsiveness]

A: Touch panel held in high temperature, high humidity environmentdemonstrated favorable responsiveness similar to that held in normaltemperature, normal humidity environment

B: Touch panel held in high temperature, high humidity environment didnot demonstrate deterioration of responsiveness, but demonstrated aslight error in detected location

C: Touch panel held in high temperature, high humidity environment wasconfirmed to demonstrate poor performance in the form of inferiorresponsiveness and error in detected location in comparison with thatheld in normal temperature, normal humidity environment

[Visibility]

A: Favorable visibility with no clouding

B: Some decrease in visibility due to clouding when transferred tonormal temperature, normal humidity environment after holding in hightemperature, high humidity environment

C: Decreased visibility due to clouding when transferred to normaltemperature, normal humidity environment after holding in hightemperature, high humidity environment

The production conditions of the examples and comparative examples areshown in Table 1, and evaluation results are shown in Table 2.

TABLE 1 Conductive Film Conductive Adhesive Sheet Base Material LayerMaterial Patterning Method Adhesive Ex. 1 100 mm PET film PEDOT coatingagent A Etching Adhesive A Ex. 2 100 mm PET film PEDOT coating agent BEtching Adhesive A Ex. 3 100 mm PET film PEDOT coating agent C EtchingAdhesive A Ex. 4  50 mm PET film (+double-sided HC layer) PEDOT coatingagent B Etching Adhesive A Ex. 5  40 mm PC film PEDOT coating agent DEtching Adhesive A Ex. 6 100 mm COP film PEDOT coating agent B EtchingAdhesive A Ex. 7 188 mm PET film (+double-sided HC layer) PEDOT coatingagent B Laser patterning Adhesive A Ex. 8 188 mm PET film (+double-sidedHC layer) PEDOT coating agent B Etching Adhesive B Ex. 9 188 mm PET film(+double-sided HC layer) PEDOT coating agent B Etching Adhesive A Ex. 10188 mm PET film (+double-sided HC layer) PEDOT coating agent B EtchingAdhesive C Ex. 11  1 mm optical reinforced glass PEDOT ink G Screenprinting Adhesive A Ex. 12 188 mm PET film (+double-sided HC layer)PEDOT ink H Gravure offset printing Adhesive A Ex. 13 188 mm PET film(+double-sided HC layer) PEDOT coating agent B UV curing + rinsingAdhesive A Ex. 14 188 mm PET film + anchor layer + foam releasing layerPEDOT coating agent B Foam release Adhesive A Comp. Ex. 1 100 mm PETfilm PEDOT coating agent B Etching Adhesive D Comp. Ex. 2 175 mm PETfilm Amorphous ITO Etching Adhesive A Comp. Ex. 3 175 mm PET filmAmorphous ITO Etching Adhesive D Comp. Ex. 4 125 mm PET film AmorphousITO Etching Adhesive D Comp. Ex. 5  50 mm PET film Post-crystalline ITOEtching Adhesive D Comp. Ex. 6 100 mm PET film PEDOT ink H Gravureoffset printing Adhesive D

TABLE 2 Conductive Laminate [Durability] Touch Panel Changes inresistance High temperature, (a) Normal (b) High [Bendability] highhumidity test [Durability] temp./normal temp./high Changes in Respon-Appearance humidity humidity resistance Appearance siveness VisibilityEx. 1 A A B A A A A Ex. 2 A A A A A A A Ex. 3 A A B A A A A Ex. 4 A A AA A A A Ex. 5 A A A A A A A Ex. 6 A A A A A A A Ex. 7 A A A A A A A Ex.8 A A B A A A A Ex. 9 A A A A A A A Ex. 10 A A B A A A A Ex. 11 A A B AB A A Ex. 12 A A B A B A A Ex. 13 A A B A A A A Ex. 14 A A B A A A AComp. Ex. 1 A B C B B A B Comp. Ex. 2 B B D C A C B Comp. Ex. 3 C B C CC B C Comp. Ex. 4 C B C C C B C Comp. Ex. 5 C B C C C A C Comp. Ex. 6 AB C B B B B

As shown in Table 1, in Examples 1 to 14 relating to laminates of apolythiophene-based conductive layer and an adhesive layer containing anacidic component of the present invention, conductive laminates wereobtained that not only demonstrated little changes in resistance values,but also did not demonstrate whitening phenomenon during sudden changesin temperature and humidity, while also demonstrating favorablebendability. In addition, touch panels using these laminates as membersthereof demonstrated favorable durability and visibility even in a hightemperature, high humidity environment. In particular, conductivelaminates containing an acrylic polymer having a carboxyl group for theacidic component of the adhesive layer demonstrated even more favorablestability in a harsh environment at high temperatures and high humidityin comparison with adhesive layers having a sulfonate group or phosphategroup for the acidic component. The effects of the present were able tobe confirmed on the basis of these findings.

In contrast, the combinations of non-thiophene-based conductive layersand adhesive layers differing from configuration of the presentinvention demonstrated considerable changes in resistance values in adurability test carried out in a high temperature, high humidityenvironment and were determined to be unsuitable. In particular,Comparative Example 2, which combined ITO with an adhesive layercontaining an acrylic polymer having a carboxyl group as a monomer unitfor the acidic component, for which favorable results were demonstratedin the examples, changes in resistance values in a high temperature,high humidity environment were remarkable, and deterioration of qualitywas prominent even in the case of using as a touch panel. On the otherhand, combinations of ITO with an adhesive layer not containing anacidic component not only demonstrated changes in resistance values in ahigh temperature, high humidity environment, but also demonstrated poorvisibility due to whitening phenomenon. Furthermore, in the case ofcombinations of a polythiophene-based conductive layer and an adhesivelayer not containing an acidic component, although there were no fataldefects observed, they were not superior to the combinations of thepresent invention.

INDUSTRIAL APPLICABILITY

The present invention makes it possible to provide a conductive laminatethat not only demonstrates little deterioration of performance even inharsh environments at high temperature and high humidity, but is alsofree of the occurrence of a whitening phenomenon occurring during suddenchanges in temperature and humidity, while also being favorable for useas a constituent member of a touch panel having superior shockresistance.

BRIEF DESCRIPTION OF THE REFERENCE SYMBOLS 1, 30: Conductive laminate10: Conductive film 11: Base material 12: Conductive layer (uniform orarbitrarily patterned layer) 20: Adhesive sheet 21: Adhesive layer 22:Releasing first base material 23: Releasing second base material 31:Second base material 32: Silver electrode (extracting electrode) 40:Cylinder for evaluating bendability 100: Liquid crystal module withelectrostatic capacitive-type touch panel 101: Covering member 102:Liquid crystal module 103: Extracting electrode wire 104: FPC connector105: Electrostatic capacitance detection circuit

What is claimed is:
 1. A conductive laminate comprising: a basematerial, first and second conductive layers uniformly or arbitrarilypatterned into a shape having uniaxial regularity laminated onto bothsides of the base material so that the patterns of the conductive layersare mutually perpendicular, a first adhesive layer provided in directcontact over the entire surface or a portion of the first conductivelayer on the outer side of the first conductive layer; a second adhesivelayer provided in direct contact over the entire surface or a portion ofthe second conductive layer on the outer side of the second conductivelayer, a first extraction electrode in contact with both the firstconductive layer and the first adhesive layer, wherein the firstextraction electrode is sandwiched between the first conductive layerand the first adhesive layer, a second extraction electrode in contactwith both the second conductive layer and the second adhesive layer,wherein the second extraction electrode is sandwiched between the secondconductive layer and the second adhesive layer, wherein the first andthe second conductive layers contain a polythiophene-based conductiveagent, the first and the second extraction electrodes are formed frommetal materials, and the first and the second adhesive layers contain anacidic component.
 2. The conductive laminate according to claim 1,wherein the extraction electrode is formed by a silver paste.
 3. Theconductive laminate according to claim 1, wherein the adhesive layercontains an acrylic polymer having a carboxyl group or a derivativethereof.
 4. The conductive laminate according to claim 1, wherein theadhesive layer contains a copolymer comprising a unit derived from oneor both of butyl acrylate or ethylhexyl acrylate and a unit derived fromacrylic acid.
 5. The conductive laminate according to claim 1, whereinthe polythiophene-based conductive agent comprises a polymer of one orboth of 3-hexylthiophene or 3,4-ethylenedioxythiophene, or a derivativethereof.
 6. A touch panel provided with the conductive laminateaccording to claim
 1. 7. The touch panel according to claim 6, whereinsaid touch panel is of the electrostatic capacitive type.